Field of the Invention
The present disclosure relates to signal emitting devices and, in particular, devices useful in friend or foe identification.
Description of Related Art
Unmanned vehicles are heavily used in various environments for reconnaissance, aerial photography, combat activities, rescue efforts, and other purposes. For example, an unmanned vehicle (“UV”) may be a reconnaissance aircraft, drone, unmanned aerial vehicle, or other like device that can be controlled remotely to fly over and/or otherwise in the vicinity of unfriendly forces, contaminated terrain, or other potentially dangerous areas. As another example, a UV may be a ground vehicle, robot, or other like device that can be controlled remotely to travel and maneuver, via land and/or sea, proximate such potentially dangerous areas. Such exemplary devices include, for example, the BigDog and other rough-terrain robots manufactured by Boston Dynamics of Waltham, Mass., the PackBot manufactured by iRobot of Bedford, Mass., and other similar devices.
Until recently, friendly reconnaissance groups, rescue groups, law enforcement groups, combat personnel or other friendly forces were the only users of UVs. However, UVs are now becoming more widely used by unfriendly or foe opposition groups. Such groups are finding it increasingly easy to equip these UVs with harmful equipment or devices, thereby putting friendly forces at risk. In some environments it can be difficult for friendly forces to distinguish between friendly UVs and foe UVs, and this difficulty can be heightened under the stress of combat situations.
It is understood that known markers, locating lasers, beacons, or other like signal emitters can be connected to and/or otherwise associated with such UVs to assist in locating and/or identifying UVs at moderate distances. However, these known signal emitters are plagued by a host of debilitating drawbacks that make them inefficient or potentially dangerous for use in combat arenas. For instance, while many signal emitters are clearly visible by conventional night vision goggles or other like viewing devices, such viewing devices are widely available and used by both friendly forces and unfriendly groups. Thus, friendly UVs equipped with known signal emitters can be detected by the unfriendly groups, making stealth operation of such UVs difficult, if not impossible.
In addition, most known signal emitters are not easily programmable or modifiable in the field, and are not configured to emit a diverse range of, for example, pulse signatures, beams, or signals. As a result, it is relatively easy for unfriendly groups to “disguise” their UVs by programming the signal emitters associated with such UVs to emit substantially the same signature or signal as that emitted by, for example, a friendly signal emitter. Such ease of deception can be very dangerous in certain environments.
Moreover, some known signal emitters, such as thermal markers or other devices emitting radiation, pulse signatures, or other signals in the thermal band, may have a limited detection range. For example, while friendly forces and UVs may be equipped with known thermal markers for friend or foe identification, the signals emitted by these devices may not be easily detected beyond a range of several hundred meters. This range may be relevant in a tightly confined arena of engagement, but such a limited range can put friendly forces at risk when UVs are used. For example, UVs such as the BigDog or unmanned aerial vehicles discussed above can move at high rates of speed and may approach or operate (in the case of unmanned aerial vehicles) at distances greater than 1 km from the combat arena. Not being able to detect a UV, or determine whether or not the detected UV is friendly, unless and until the UV is within several hundred meters of, for example, an engagement arena or other area occupied by friendly forces, can put these forces at serious risk.
Moreover, devices used in military, law enforcement, surveillance, and other industries may also employ signal emitters in various environments to mark an object or location, and/or to otherwise convey information about the object or location. Such devices may include, for example, unattended ground sensors/devices, self-righting camera balls such as the Eye Ball R1 Surveillance Ball manufactured by Remington Arms Company, Inc. of Madison, N.C., and other like devices. Moreover, such information may include, for example, whether or not to engage the object, or the location of a target, hidden resources, friendly forces, or checkpoints along a path. However, known signal emitters may not be suitable for use with such devices due to the deficiencies discussed above. For example, signals emitted by thermal markers may not be easily seen from great distances, thus making locating such devices difficult.
The various embodiments set forth in the present disclosure are directed toward overcoming the problems discussed above.